Hello Srija !

There are many scholars , which have presented many theories with regard to this field ,  the last theory that have been presented , presents following observations ,

1. Evidences show that complex decisions were taken and implemented in the Harappan society.
2. Plans and layouts of the city were prepared under the guidance and supervisions of the rulers. Big buildings, palaces, forts, tanks, wells, canals and granaries were constructed.
3. The rulers looked after the welfare of the economy.
4. Rulers were expected to provide relief during natural calamity.
5. During foreign aggression, the rulers defended the city.
6. The ruler used to issue common acceptable coins or seals, weights and measurements.
7. Cleanliness was the responsibility of the ruler. Roads, lanes and drains were also constructed.

Hope it helps !

If you want any further explanation , please feel free to ask.

Hope it helps !